Do all wisdom teeth have to be removed even if they don't hurt?

No. A wisdom tooth that has erupted straight, cleans easily, and has an opposing tooth to chew against can usually stay. However, we recommend preventive extraction even without symptoms when 1) the tooth is tilted or impacted and a toothbrush cannot reach it, 2) the wisdom tooth or the molar in front of it repeatedly develops cavities or gum inflammation, or 3) there are signs of a cyst around it. Impacted wisdom teeth become more difficult to remove once problems develop, so it is best to take a panoramic X-ray first and then decide whether to extract.